16" X 10" ALUMINUM RETURN FILTER GRILLE FOR 1" FILTER - EASY AIRFLOW - LINEAR BAR GRILLES w6h6 But for plumbing it will Compatible with Duct 4" Product Details Size 32 LO246

But for plumbing it will fit onto a pipe that is 1/4" on the "inside" (ID) which equals to 1/2 on the outside

Upgrade to a new standard of air quality and aesthetics with our Aluminum Ceiling Diffuser

With its practical roll-formed lock construction on all four sides

+ Product Details Size - 10"w X 12"h is the size for the duct opening measurement only

it's a solution

16" X 10" ALUMINUM RETURN FILTER GRILLE FOR 1" FILTER EASY AIRFLOW LINEAR BAR GRILLES w6h6 But for plumbing it will Compatible with Duct 4" Product Details Size 32 LO246 But for plumbing it will fit onto a pipe that is 1 4" on the "inside" (ID) which equals to 1 2 on the outside Upgrade to a new standard of air quality and aesthetics with our Aluminum Ceiling Diffuser